The United States is operating a secret base out of Saudi Arabia and used it to launch a CIA drone strike in 2011 that killed US-born al Qaeda leader Anwar Al Awlaki, according to a media report.

The Washington Post, in a report on Wednesday, said the Middle East base was set up two years ago as part of US officials effort to ramp up its search for members of the militant group.

Representatives for the CIA declined to comment on the report.

The disclosure is the latest on the nation's controversial drone strike policy ahead of White House counterterrorism chief John Brennan's Senate confirmation hearing on Thursday (local time) over his nomination to become CIA director.

White House officials had asked the newspaper to refrain from revealing the strategic base in the powerful oil nation, citing concerns that the information could undermine the hunt, the Washington Post said in its story.

"The Post learned Tuesday night that another news organisation was planning to reveal the location of the base, effectively ending an informal arrangement among several news organisations that had been aware of the location for more than a year," it wrote.

The New York Times' lead story on Wednesday also reported that Brennan worked closely with Saudi Arabia to gain approval to establish a secret drone base there.

A memo released earlier this week raised fresh questions about the drone policy. The memo, first reported by NBC News, outlined the legality of drone strikes to kill US citizens abroad, an issue now likely to be raised at Brennan's hearing.